seam side up or down?

Maybe everybody but me knows the answer to this question but here goes: Do I place the dough into a banneton/brotform to proof seam-side down or up? Since it will ultimately be flipped for baking it seems to me the skin should be down in the brotform. But I tried that yesterday, after pinching the seam as best I could. My pinching wasn't enough to really hold it all together. The bread turned out okay but I found it a bit tough, despite the fact that the bread rose just fine. That may have nothing to do with brotform proofing method, but I'm looking for answers.

So... Seam side down, or up, in the brotform?

And does anyone have ideas why a chocolate bread (organic white all purpose flour) may have turned out "tough"?